Wrench.



Patented Apr. 11, 1911.

L. B. 'BOATWRIGHR WRENCH.

APPLIOATION FILED Nov. s, 1910.

LAUREL E. BOATWRIGI-IT, OF GRANGER, IOWA.

WRENCH.

Specification of Letters Patent.

Patented Apr. 11, 1911.

Application filed November 3, 1910. Serial No. 590,913.

To all whom it may concern:

.,Be it `known that I, LAUREL E. BOAT- wRIGH'r, citizen of the United States of America, and resident of Granger, Dallas county, Iowa, have invented a new and useful W'rench, of which the following is a specication.

The object of this invention is to provide an improved construction for wrenches whereby lateral force applied to the handle in one direction increases the gripping relations of the jaws to the nut being acted upon by the wrench.

My invention consists in the construction, arrangement and combination of elements hereinafter set forth, pointed out in my claims and illustrated by the accompanying drawing, in which- Figure 1 is a plan at one side and Fig. 2 a plan atthe other side of the complete wrench. Fig. 3 is a cross-section on the indicated line 3-3 of Fig. 1. Fig. 4 is a goss-section on the indicated line 4 4 of In the construction of the tool as shown the numeral 10 designates a jaw member which is formed with a lateral extension or wing 11, which wing is of a thickness approximating to one-half that of the jaw member.

The numeral 12 designates a mating jaw member which is formed with a wing 13 approximating in thickness to one-half that of the jaw member. The wing 13 overlies and extends partially across the wing 11, a cavity or recess 14 existing between the inner margin of the wing 13 and the adjacent margin of the rear portion of the jaw member 10. The wings 11, 13 are pivoted together by means of a rivet 15 adjacent to the notch or opening existing between the forward portions of the jaw members and at one side of the median line of said jaw members, and one end portion of said rivet is pivotally connected by a strap 16 to the central portion of the jaw member 10 and extends across said median line. A handle 17 is mounted with its forward end portion in the recess or cavity 14 and is pivoted to the wing 11 by a rivet 18. The handle 17 and rivet 18 lie on the opposite side of the median line of the jaws from the rivet 15 connecting said jaws. The handle 17 is formed with a curved margin 19 at its forward. end, the curve of which margin is eccentric to the rivet 18. The curved margin or face 19 of the handle 17 is adapted toengage a correspondingly curved inner margin 2O on the wing 13, which margin 20 is located on and intersects a right line form-4 ing the median line of the jaws. The forward end portion of the handle 17, in front of the rivet 18, is pivotally connected to one 18, two points on said are being the centers of the pivots whereby said strap is connected to the handle and wing. A line intersecting the fulcrum 18 and pivotal connection between the strap 21 and wing 13 is at right angles to the median line of the jaws normally and lies normally at right angles to a line parallel with said median line and intersecting said pivotal connection and the rivet 15. It will be observed that the pivotal connection between the jaws is laterally removed to the same side of the median line as the pivotal connection between the wing 13 and strap 21; that the fulcrum 18 and pivotal connection between the forward end of the handle and the strap 21 are on a line parallel with and on the opposite side of the median line of the jaws; that the fulcrum 18 and pivotal connection between the strap 21 and wing 13 are on the same transverse line; and that the strap l21 crosses the median line of the jaws obliquely and at the same time crosses a line intersecting the fulcrum 18 and rivet 15.

In the practical use of the device as shown in Fig. 1 manual force applied to move the handle in the direction of the arrow at the extremity thereof will cause the forward end portion of said handle to act through the strap 21 and also through the co-acting curved faces 19, 20 to an oscillation of the jaw 12 and wing 13 on and relative to the wing 11 and jaw 10, thus tending to close or narrow the space or notch between the jaws and exert an augmented gripping influence on a nut contained in said notch. This operation would be employed in unscrewing a right-threaded nut or bolt. In tightening a right-threaded nut or bolt the tool would be inverted as shown in Fig. 2, at which time manual force applied to move the l handle in the direction of the arrow at the outer end thereof ywould in like manner effect an oscillation of the jaw l2 and tend to cause said aw to tighten on and gripthe nut.

I claim as my inventionl. A wrench comprising jaws formed with wings halved and pivoted together, there being a cavity formed between one wing and the opposite jaw at one side of the inedianline 4of the jaws, means for pivoting the wingsof the jaws together on the opposite sideof saidniedian line, a handle pivoted to oney of the wings at the rear and across the median line of the jaws from the pivotal connection of the wings, said handle formed with a ,bearing surface eccentric to its pivot and adapted to engage a bearing snrface on one of the wings on the median line of the'jaws, anda link pivotally connecting the forward end of said handle with the'jrea'rportion ofthe adjacent wing, one end'of said link being on the median line ofthe handle intersecting the fulcrum of the n handle, vsaid link extending across a right line intersecting the pivot of the wings andthe pivot ofthe handle and also extending obliqiiely across the median line of .the jaws andlhaving its said pivotal connection with the wing on a right line intersecting the nfu'lcrum ofthe handle, said latter right line being at right angles to the median line of the jaws.

2. A wrench comprising jaws formed with wings halved and pivoted together, there being a cavity formed between one wing and the opposite jaw at one side of the median line of the jaws, means for pivoting the wings of the aws together on the opposite side of said median line, a handle pivoted to one of the wings at the rear and across the median line of the aws from the pivotal connection of the wings, saidhandle being seated in said cavity, said'handle formed with a bearing surfaceeccentric to its pivot and adapted to engage a bearing surface on one of the wings on the median line ofthe jaws, and a link pivotally connectingithe forward end of said handle with the rear-portion of the adjacent wing, said-link extending across a right line intersecting the. pivot ofthe wings and Athe `pivot of the handle', togetherwith a stay strap pivot-ally conneoting one of the aws to the wingof the other jaw coincident with the pivotalconnection of the jaws.

Signed by me at Des Moines, Iowa, this twenty-second day of September, .1910.

Witnesses:

S. C. SWEET,

EARL SINCLAIR,

Copies yof thi-'s patent may be obtained forA ve cents each, by addressing the Commissioner of Patents,

` 'l' Washington, D. C. 

